I'm a native speaker of British English, and I often write documentation and copy for an international audience. I understand the differences between British and American English enough to "translate" a document for consumption by Americans. There's no slang or local cultural references, so it's just a question of removing the u's and changing the odd word (boot to trunk, and so on).
How can I do the same for Australian readers? Should I start from the British or American version of the source? Are there even more word replacements for me to consider? (Don't try to list them here; I just want to know the scale of the problem.)
I've seen that there is a similar question for Canadian English.